The present invention relates to a system for setting a spatial position of a vehicle relative to a foundation on which the vehicle is standing with its wheels, in particular in a wind tunnel.
German patent document DE 198 15 312 C1 discloses a device, by which a vehicle can be placed into a test section of a wind tunnel. During the measurement process, this system is deactivated by transferring it into a stand-by position, which does not influence and/or disturb the measuring process.
It is known from German patent document DE 42 38 691 C2 to place the wheels of a vehicle in such a position in wind tunnel models that they are self-stabilizing in order to automatically compensate for any disturbances that may develop.
In wind tunnel testing of motor vehicles, in particular sports vehicles or racing vehicles, it may be necessary to change the position and orientation of the vehicle relative to the foundation on which the vehicle is standing with its wheels. This may be done in order, for example, to simulate the effects caused by changes in the vehicle's position and orientation based on the dynamic processes while operating the vehicle, such as the processes of steering, braking and accelerating. It may also be done in order to test the aerodynamic parameters of the vehicle. In particular, in racing vehicles, where the distance between the vehicle and the ground is negligible, one would expect dramatic aerodynamic changes with a change in position in the millimeter range.
The present invention focuses on the problem of providing a possibility—for setting a position and orientation of a vehicle relative to a foundation, on which the vehicle is standing with its wheels—that is especially appropriate for wind tunnel measurements.
This problem is solved by providing a system for setting a spatial position of a vehicle relative to a foundation on which the vehicle is standing with its wheels, in particular in a wind tunnel. A plurality of linear actuating devices are respectively assigned to each one of the wheels and are mounted on the vehicle in the area of the respective wheel. In the area of the respective wheel, a distance between the foundation and a vehicle chassis can be set with the linear actuating devices. A plurality of measuring devices are respectively assigned to each one of the actuating devices for determining the distance between the foundation and the vehicle chassis in the area of the respective wheel. A control unit is coupled to the measuring devices for actuating the actuating devices. Advantageous embodiments are further described herein.
The invention is based on the general idea of assigning a linear actuating device to a plurality of wheels (or to all of the wheels) of a vehicle. By using the linear actuating device, a distance between the foundation and a vehicle chassis can be set in the area of the respective wheel. Furthermore, the actuating devices may be assigned measuring devices, with which the distance between the foundation and the vehicle chassis can be determined in the area of the respective wheel. In addition, there is a control unit, which is coupled to the measuring devices, for actuating the actuating devices. The inventive adjusting device makes it possible to set the distance between the foundation and the vehicle chassis at each wheel that is equipped with such an actuating device. Therefore, the individual actuating devices can be actuated independently of each other, so that by using the control unit it is possible to set different position and orientation parameters of the vehicle, such as a vehicle to ground distance, thus, in particular, the distance between the foundation and a specific reference point (preferably arranged on the vehicle floor) on the vehicle chassis; a vehicle rolling angle, thus the tilt of the vehicle in relation to the foundation about a vehicle longitudinal axis; as well as a vehicle pitch angle, thus the tilt of the vehicle in relation to the foundation about a vehicle transverse axis.
Therefore, an embodiment in which the control unit is disposed externally with respect to the vehicle is especially advantageous. In particular, the control unit may be disposed in a control center of the wind tunnel. In this way it is possible, in particular, to change the position and orientation of the vehicle in relation to the foundation without having to interrupt the measuring process. In this way, the test bed periods and, thus, the test bed costs, may be significantly reduced. To this end, actuating devices that form with the respective measuring device one unit, which can be, in particular, pre-mounted in its entirety and can be attached as one unit to the vehicle, are especially advantageous. For example, the respective measuring device may be attached to the respective actuating device or installed or integrated therein.
Other important features and advantages of the invention follow from the dependent claims, the drawings and the respective description of the figures with reference to the drawings. It is clear that the aforementioned features and those features to be explained below can be used not only in the respective cited combination, but also in other combinations or alone without departing from the scope of the present invention.
Preferred embodiments of the invention are depicted in the drawings and are explained in detail in the following description. In this case identical reference numerals refer to the same or similar or functionally identical components.